Unable to export or import .sif through Siebel Tools

Team,

All of sudden, Not able to import or export any objects from Siebel tools server. (No changes on DB side.)

Getting following error:

"Error retrieving next record from the database.(SBL-DBC-00104)"  There is no error from siebel UI.

As per detail tools log: after below query, error is occurring.

SELECT /*+ ALL_ROWS */

      T2.CONFLICT_ID,

      T2.LAST_UPD,

      T2.CREATED,

      T2.LAST_UPD_BY,

      T2.CREATED_BY,

      T2.MODIFICATION_NUM,

      T2.ROW_ID,

      T7.AGENT_FLG,

      T6.CURR_PRD_OBJ_NAME,

      T7.EMAIL_ADDR,

      T7.EMP_FLG,

      T7.FAX_PH_NUM,

      T7.FST_NAME,

      T7.LAST_NAME,

      T5.LOGIN,